JPH11257450A - Toroidal type continuously variable transmission - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent a loading nut from being loosened by arranging a radial needle in contact between an outside face of a support shaft inserted from an end part on the side where the loading nut of a torque input shaft is threadedly attached, into a through hole and an inner wall face of the through hole. SOLUTION: A support shaft 2 is protrudively arranged inside a casing wall face 1 and a plurality of needle rollers 5 are arranged in contact across the circumferential direction between the outside face of the support shaft 2 inserted from the end of a torque input shaft 4 on the side where a loading nut 3 is threadedly attached, to a through hole and the inside wall face of the through hole. The torque input shaft 4 is rotatably and pivotally mounted on a radial needle bearing constituted of the outside face of the support shaft 2, the inner wall of the through hole, and a plurality of needle rollers 5. When the input torque is abruptly changed, this constitution can dispense with loosening of the loading nut threadedly attached to the torque input shaft end part and improve the reliability.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a structure for preventing a loading nut screwed into an end of a torque input shaft provided in a toroidal-type continuously variable transmission used as, for example, a transmission of a motor vehicle. .

[0002]

2. Description of the Related Art Toroidal-type continuously variable transmissions, which have been studied for transmissions mainly for automobiles, include an input disk and an output disk each having mutually opposite surfaces each having an arc-shaped concave cross section. A toroidal speed change mechanism having a structure combining a rotatable power roller sandwiched between two disks is provided. The input disk is locked and mounted so as to be integrally rotatable with respect to the torque input shaft and restricted from moving in the direction of the torque input shaft, while the output disk is mounted relatively to the torque input shaft. It is mounted opposite the input disk so as to be rotatable and restricted from moving away from the input disk.

In the above-described toroidal transmission, when the input disk rotates, the output disk rotates reversely via the power roller. Therefore, the rotational motion input to the torque input shaft is output as a rotational motion in the opposite direction. It is transmitted to the disk and taken out. At this time, the inclination from the torque input shaft to the output gear is increased by changing the inclination angle of the rotating shaft of the power roller so that the peripheral surface of the power roller comes into contact with the vicinity of the outer periphery of the input disk and the vicinity of the center of the output disk, respectively. Conversely, the torque input shaft is changed by changing the inclination angle of the rotation shaft of the power roller so that the peripheral surface of the power roller comes into contact with the vicinity of the center of the input disk and the vicinity of the outer periphery of the output disk, respectively. From the gear to the output gear. In addition, for the gear ratio between the two,
By adjusting the angle of inclination of the rotating shaft of the power roller appropriately, it can be obtained almost steplessly.

[0004] A torque input shaft on which the toroidal type transmission mechanism is mounted is rotatably connected to a casing via a bearing, and lubricating oil is sent to the central portion of the torque input shaft to each part of the toroidal type continuously variable transmission. A through hole is formed along the longitudinal direction of the shaft.

In a toroidal transmission mechanism that transmits a driving force by physical contact of each member, frictional rotation between an input disk and a power roller and between a power roller and an output disk is maintained to prevent a reduction in transmission efficiency. There must be. For this reason, a pressing device such as a loading cam capable of generating a pressing force in a direction along the torque input shaft in accordance with a change in the rotational torque input to the input disk is mounted on an end of the torque input shaft. Further, a preload means such as a disc spring is disposed at one end of the torque input shaft, and is maintained in a biased state by being compressed by a loading nut screwed to one end of the torque input shaft. As a result,
Even when the rotational torque input to the input disk is kept at a substantially constant value and no pressing force is generated by the pressing device, a constant amount of pressing force along the torque input shaft is always applied from the preload means to the input disk. Therefore, slip between the input disk / power roller and between the power roller / output disk is reliably prevented.

FIG. 5 shows an example of the overall configuration of such a toroidal-type continuously variable transmission. The toroidal-type continuously variable transmission exemplified here is a double-cavity type provided with two sets of the above-mentioned toroidal-type transmission mechanisms in order to cope with a larger input torque, and an output disk of each toroidal-type transmission mechanism has: The torque input shaft 4 is attached to the torque input shaft 4 so that they are connected in parallel so as to face each other. FIG. 6 is an enlarged view of the vicinity of the mounting portion of the loading nut 3 of this configuration example. The end of the torque input shaft 4 is inserted into a support hole formed in the casing wall surface 1 together with the loading nut 3 screwed on the outer surface, and the outer surface of the loading nut 3 and the inner wall surface of the support hole. The plurality of needle rollers 5 are arranged in contact with each other in the circumferential direction. The torque input shaft 4 is rotatably supported by a radial needle bearing composed of the outer surface of the loading nut 3, the inner wall surface of the mounting hole, and a plurality of needle rollers 5.

[0007]

In the toroidal-type continuously variable transmission as described above, the loading nut is brought into contact with the outer peripheral surface of the end of the torque input shaft only by the thrust force based on the frictional contact between the thread and the thread groove. It is screwed. For this reason,
For example, because the input torque to the toroidal transmission mechanism fluctuates suddenly due to sudden start or sudden acceleration of the vehicle, etc.,
When a force for relatively rotating the torque input shaft and the loading nut acts, there is a risk that the loading nut may be loosened. The decrease in the compression ratio of the preload means due to the loosening of the loading nut directly causes the loss of frictional contact between the input disk / power roller and the power roller / output disk, greatly increasing the reliability of the toroidal type continuously variable transmission. It causes problems such as lowering.

SUMMARY OF THE INVENTION The present invention has been made under the above circumstances, and an object of the present invention is to provide a screw at the end of the torque input shaft even when the input torque to the torque input shaft changes rapidly in a short time. It is an object of the present invention to provide a toroidal-type continuously variable transmission that can prevent a loaded loading nut from being loosened.

[0009]

According to the present invention, there is provided at least one set of a toroidal type speed change mechanism comprising an input disk, an output disk, and a power roller abutted and held between these disks to transmit a driving force between the two disks. Has a torque input shaft mounted thereon, wherein the torque input shaft rotatably coupled to a casing of the toroidal type continuously variable transmission,
The present invention relates to a toroidal-type continuously variable transmission including a through hole extending in a longitudinal direction formed in a center portion, and a loading nut screwed to an outer surface of one end portion. A crimped piece provided on the inner wall surface of the loading nut at the edge of the torque input shaft end portion is caulked into a notch formed at a position facing the scaly piece on the outer surface of the torque input shaft, and the casing is formed. An outer surface of the support shaft inserted into the through-hole from the end of the torque input shaft on which the loading nut is screwed, and a support shaft protruding from the wall surface of the torque input shaft. This is achieved by arranging the radial needle in contact with the wall surface. In addition, the above object of the present invention is to form a scaly piece provided on the inner wall surface of the loading nut at the edge of the torque input shaft end portion at a position facing the scaly piece on the outer surface of the torque input shaft. An outer surface of a loading nut screwed to an end of the torque input shaft inserted into the support hole, while being caulked in the notch portion and forming a support hole in a wall surface of the casing, and the support hole. The same can be achieved by arranging the radial needle in contact with the inner wall surface.

[0010]

DESCRIPTION OF THE PREFERRED EMBODIMENTS In a toroidal type continuously variable transmission according to the present invention, a scale is provided on an inner wall surface of a loading nut and a notch is formed on an outer surface of an end of a torque input shaft opposed to the scale. Further, the present invention is characterized in that the scale-shaped piece is crimped into the notch to prevent the loading nut from being loosened. Therefore, other components such as the toroidal type transmission mechanism can be used in the same manner as the conventional toroidal type continuously variable transmission.

FIG. 1 is an enlarged view of the vicinity of a loading nut mounting portion of an embodiment of a toroidal type continuously variable transmission according to the present invention. In this embodiment, a support shaft 2 is protruded from the inside of a casing wall 1, and the support shaft 2 inserted into the through hole from the end of the torque input shaft 4 on the side where the loading nut 3 is screwed. A plurality of needle rollers 5 are arranged in a circumferential direction between the outer surface of the needle roller and the inner wall surface of the through hole. The torque input shaft 4 is rotatably supported by a radial needle bearing composed of the outer surface of the support shaft 2, the inner wall surface of the through hole, and a plurality of needle rollers 5. In this embodiment, a circumferential groove surface for guiding a plurality of needle rollers 5 is formed on the outer surface of the support shaft 2 and the inner wall surface of the through hole, respectively, and the radial needle The function as the outer ring and the inner ring of the bearing can be more reliably exhibited. Further, the casing wall surface 1 integrated with the support shaft 2 is detachable from the casing body 6, and these are integrally fastened by bolts 7 or the like, so that the convenience at the time of assembly and maintenance is improved. ing.

FIG. 2 shows the torque input shaft 4 near the loading nut mounting portion in the embodiment of the present invention shown in FIG.
It is sectional drawing seen from the edge part direction. On the inner wall surface of the loading nut 3, the edge on the side located at the end of the torque input shaft 4 at the time of screwing is stretched thinly along the direction of the torque input shaft 4 from the end face of the loading nut 3 over the circumferential direction. Has formed. When the support shaft 2 is inserted, the outer surface of the end of the torque input shaft 4 adjacent to the scale-like piece 8 is partially cut away thinly in the circumferential direction to form a notch 9. When assembling the toroidal type continuously variable transmission of the present invention, first, the loading nut 3 arranged at the end of the torque input shaft 4 is screwed and integrated with the screw surface on the outer surface of the torque input shaft 4, and then, Loading nut 3
Of the torque input shaft 4 is crimped.

As a result of caulking the loading nut 3 in this way, in order to cause relative rotation between the loading nut 3 and the torque input shaft 4, physical deformation or destruction of the scale-like piece 8 and the notch 9 is indispensable. Become. Therefore, loading nut 3
The coupling strength of the loading nut 3 is dramatically improved due to the rapid change of the input torque to the toroidal transmission mechanism.
Can surely be prevented from being loosened. Further, in the above-described embodiment, the radial needle bearing is accommodated in the through hole of the torque input shaft 4, so that a spatial margin around the loading nut 3 is increased, and the degree of freedom in arranging each accessory is increased. Since the dimensions (particularly the diameter) of the bearing itself are reduced, the number of needle rollers 5 to be used can be reduced.
This makes it possible to reduce the size and weight of the entire toroidal-type continuously variable transmission.

FIG. 3 is an enlarged view of another embodiment of the toroidal-type continuously variable transmission according to the present invention in the vicinity of a loading nut mounting portion. In this embodiment, similarly to the configuration example shown in the description of the prior art, a support hole is formed in the casing wall surface 1 and the end of the torque input shaft 4 is joined with the loading nut 3 screwed to the outer surface. Inserted into the support hole. Further, between the outer surface of the loading nut 3 and the inner wall surface of the support hole, a plurality of needle rollers 5 are arranged in circumferential contact with each other. Multiple needle rollers 5
The torque input shaft 4 is rotatably supported by a radial needle bearing composed of the following. Furthermore, a groove surface extending in the circumferential direction is formed on each surface of the radial needle bearing with which the needle roller 5 abuts, thereby improving the guide function as the outer ring and the inner ring of the bearing.

Also in this embodiment, FIGS. 1 and 2
In the same manner as shown in the figure, the edge of the inner wall surface of the loading nut 3 which is located in the direction of the end of the torque input shaft 4 has a thin scale 8
It is stretched into a shape, and is caulked to a notch 9 formed on the outer surface of the end of the torque input shaft 4, thereby eliminating the loosening of the loading nut 3.

When caulking is used to fix the loading nut 3 to the torque input shaft 4 as in each of the above-described embodiments, a part of the thrust force of the loading nut 3 reduces the scale-like piece 8 and the notch 9. , So that the tightening force required to compress the preload means such as a disc spring is smaller than in the past. As a result, a secondary effect that the tightening of the loading nut 3 becomes unnecessary when assembling the toroidal-type continuously variable transmission is obtained.

According to the configuration of the present invention, the loosening of the loading nut 3 can be effectively prevented even with one caulking. Therefore, in each embodiment described above,
Although only one notch 9 is provided in the circumferential direction of the torque input shaft 3, a plurality of notches 9 are provided to
By caulking at a plurality of locations, the effect of preventing the loading nut 3 from loosening can be more reliably exerted. In this case, in order to improve the rotational balance of the torque input shaft 4, it is desirable to arrange the notches 9 so as to be evenly distributed in the circumferential direction of the torque input shaft 4.

Generally, in order to prevent the nut from being loosened, in addition to caulking, for example, through holes are formed in the side surfaces of the nut and the mounting member so as to penetrate in the radial direction of the nut, and these through holes are formed. A method of preventing relative rotation between the two by a pin inserted therein (see FIG. 4 (A)) or a hexagonal hole which penetrates the nut by forming a stop hole penetrating from the outer surface to the inner wall surface A method of preventing loosening of the nut by frictional contact between the tip of the set screw and the outer surface of the mounting member (see FIG. 4B) or the like is used. In order to prevent the pin 11 or the set screw 12 from coming off, respectively, FIG.
In the method (A), both ends of the pin 11 are crushed,
In the method shown in FIG. 4B, a small fixing bolt 13 is fitted in the hexagonal hole of the set screw 12. Since these methods require much more labor and time when processing and mounting parts, they are practically applied to the loading nut 3 of the toroidal type continuously variable transmission. It is difficult, but can achieve the same purpose as the present invention.

The inner wall surface of the loading nut 3 is
Since it is coupled to the outer surface of the torque input shaft 4 by the screw thread and the thread groove, it is not preferable to have an excessive hardness. Further, the scale-like piece 8 portion to be caulked in the notch 9 on the outer surface of the torque input shaft 4 needs to have a certain degree of softness for plastic deformation. On the other hand, at the end face of the loading nut 3 which comes into surface contact with another member such as a disc spring or a spacer after the assembling, the influence of damage due to wear must be taken into consideration. Is desirable. As described above, the hardness conditions required for the loading nut 3 are opposite to each other depending on the location.
In the toroidal-type continuously variable transmission according to the present invention, in order to realize the loading nut 3 having different hardness for each part, carburizing heat treatment in which a part is carburized and partial high-frequency heat treatment are performed.

[0020]

As described above, according to the toroidal-type continuously variable transmission of the present invention, even if the input torque to the toroidal-type transmission mechanism fluctuates rapidly, it is screwed to the end of the torque input shaft. There is no loosening of the loading nut. Therefore, the reliability of the toroidal type continuously variable transmission is improved. Further, in the toroidal type continuously variable transmission according to the present invention, the tightening force of the loading nut required for compressing the preload means such as a disc spring can be reduced, and additional tightening is not required. Is reduced.

[Brief description of the drawings]

FIG. 1 is an enlarged cross-sectional view of the vicinity of a loading nut mounting portion of an embodiment of a toroidal-type continuously variable transmission according to the present invention.

FIG. 2 is a cross-sectional view of the vicinity of a loading nut mounting portion of the toroidal-type continuously variable transmission of the present invention shown in FIG. 1 as viewed from a torque input shaft end direction.

FIG. 3 is an enlarged sectional view showing the vicinity of a loading nut mounting portion in another embodiment of the toroidal-type continuously variable transmission according to the present invention.

FIG. 4 is a simplified diagram for explaining another loading nut mounting method having the same effect as that of the toroidal type continuously variable transmission according to the present invention.

FIG. 5 is an axial sectional view showing an entire configuration example of a conventional toroidal-type continuously variable transmission.

FIG. 6 is an enlarged sectional view of the vicinity of a loading nut mounting portion of the conventional toroidal-type continuously variable transmission shown in FIG.

[Description of Signs] 1 Casing wall surface 2 Support shaft 3 Loading nut 4 Torque input shaft 5 Needle roller 6 Casing body 7 Bolt 8 Scale-like piece 9 Notch portion 11 Pin 12 Set screw 13 Small fixing bolt

Claims (2)

[Claims] 1. A torque input shaft equipped with at least one set of toroidal type transmission mechanisms comprising an input disk, an output disk, and a power roller abutted and held between these disks and transmitting a driving force between the two disks. The torque input shaft rotatably coupled to a casing of the toroidal-type continuously variable transmission is screwed into a longitudinally extending through hole formed in the center and an outer surface of one end. In the toroidal type continuously variable transmission including the loading nut, the scale-like piece provided on the edge of the inner surface of the loading nut at the end of the torque input shaft is opposed to the scale-like piece on the outer surface of the torque input shaft. The casing is caulked in a notch formed at a position, and a support shaft is protruded from a wall surface of the casing, and the loading nut of the torque input shaft is A toroidal type in which a radial needle is disposed between an outer surface of the support shaft inserted into the through hole from an end on which the screw is attached and an inner wall surface of the through hole. Continuously variable transmission. 2. A torque input shaft equipped with at least one set of toroidal transmission mechanisms having an input disk, an output disk, and a power roller abutted and held between these disks and transmitting a driving force between the two disks. The torque input shaft rotatably coupled to a casing of the toroidal-type continuously variable transmission is screwed into a longitudinally extending through hole formed in the center and an outer surface of one end. In the toroidal type continuously variable transmission including the loading nut, the scale-like piece provided on the edge of the inner surface of the loading nut at the end of the torque input shaft is opposed to the scale-like piece on the outer surface of the torque input shaft. A support hole is formed in a wall surface of the casing, and the torque input shaft is inserted into the support hole. A toroidal-type continuously variable transmission, wherein a radial needle is disposed between an outer surface of a loading nut screwed to an end and an inner wall surface of the support hole.